#打印三角形
size = int(input("请输入三角形长度："))
i =  0
print("左下")
while size >= i:
    print("* " * i,)
    i += 1

print("左上")
while size <= i+1:
    i -= 1
    print("* " * i,)

print("右上")
i = size
while i >= 1:
    print(" "*(size -i)+"*" * i,)
    i -= 1

print("右下")
i = 1
while i <= size:
    print(" "*(size -i)+"*" * i,)
    i += 1


